hey! dont worry ur pc specs are better then mine!
Intel Celeron D. 2.93ghtz, 512mb RAM, Geforce 5200...<now thats a crappy pc!
For a good vid card a Radeon X1600 PRO AGP is a good card, has 512mb of memory a little on the expensive side though........but it will give you everything you need
check it out:
http://www.tigerdirect.com/applicati...110&CatId=2234
also the chances of you needing a new cpu is low if ur current one is a socket like 775 (most common on p4's) because you can get a socket 775 mobo that uses DDR and has pci-express slots for around 80-150 USD